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authorAnup Patel <anup@brainfault.org>2018-12-04 15:59:52 +0530
committerDaniel Lezcano <daniel.lezcano@linaro.org>2018-12-18 22:22:23 +0100
commit92e0d143fdef1faa7560c93fb0d6cd6c61da88ee (patch)
treef52b5e219877dbd0b2e646c63a1c8bbb63dde25f /drivers/clocksource
parent4f352d1fc5a8d3220e29766a26172eff34867014 (diff)
downloadlinux-0-day-92e0d143fdef1faa7560c93fb0d6cd6c61da88ee.tar.gz
linux-0-day-92e0d143fdef1faa7560c93fb0d6cd6c61da88ee.tar.xz
clocksource/drivers/riscv_timer: Provide the sched_clock
Currently, we don't have a sched_clock registered for RISC-V systems. This means Linux time keeping will use jiffies (running at HZ) as the default sched_clock. To avoid this, we explicity provide sched_clock using RISC-V rdtime instruction (similar to riscv_timer clocksource). Signed-off-by: Anup Patel <anup@brainfault.org> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig2
-rw-r--r--drivers/clocksource/riscv_timer.c9
2 files changed, 10 insertions, 1 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index c57b156f49a23..a4ae339e01011 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -599,7 +599,7 @@ config ATCPIT100_TIMER
config RISCV_TIMER
bool "Timer for the RISC-V platform"
- depends on RISCV
+ depends on GENERIC_SCHED_CLOCK && RISCV
default y
select TIMER_PROBE
select TIMER_OF
diff --git a/drivers/clocksource/riscv_timer.c b/drivers/clocksource/riscv_timer.c
index 084e97dc10ed9..431892200a087 100644
--- a/drivers/clocksource/riscv_timer.c
+++ b/drivers/clocksource/riscv_timer.c
@@ -8,6 +8,7 @@
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/irq.h>
+#include <linux/sched_clock.h>
#include <asm/smp.h>
#include <asm/sbi.h>
@@ -49,6 +50,11 @@ static unsigned long long riscv_clocksource_rdtime(struct clocksource *cs)
return get_cycles64();
}
+static u64 riscv_sched_clock(void)
+{
+ return get_cycles64();
+}
+
static DEFINE_PER_CPU(struct clocksource, riscv_clocksource) = {
.name = "riscv_clocksource",
.rating = 300,
@@ -97,6 +103,9 @@ static int __init riscv_timer_init_dt(struct device_node *n)
cs = per_cpu_ptr(&riscv_clocksource, cpuid);
clocksource_register_hz(cs, riscv_timebase);
+ sched_clock_register(riscv_sched_clock,
+ BITS_PER_LONG, riscv_timebase);
+
error = cpuhp_setup_state(CPUHP_AP_RISCV_TIMER_STARTING,
"clockevents/riscv/timer:starting",
riscv_timer_starting_cpu, riscv_timer_dying_cpu);